Submission #566730

#	Time	Username	Problem	Language	Result	Execution time	Memory
566730		Ooops_sorry	Road Closures (APIO21_roads)	C++14	31 / 100	2095 ms	59384 KiB

roads

#include<bits/stdc++.h>
#ifndef LOCAL
    #include "roads.h"
#endif

#define ld long double
#define ll long long
#define pb push_back

using namespace std;

const int N = 1e5 + 10;
const ll INF = 1e18;
vector<pair<int,ll>> g[N];
ll e[N], val[N];
map<int, pair<ll, ll>> dp[N];
int k, n;

void dfs(int v, int p) {
    vector<int> arr;
    ll sum = 0;
    int r = -1;
    for (auto to : g[v]) {
        if (to.first != p) {
            e[to.first] = to.second;
            dfs(to.first, v);
            arr.pb(to.first);
        }
    }
    sort(arr.begin(), arr.end(), [&](int a, int b){return dp[a].size() > dp[b].size();});
    /*if (arr.size() > 0 && dp[arr[0]].size() > arr.size() + 1) {
        r = arr[0];
        swap(dp[v], dp[r]);
    }*/
    int sz = arr.size();
    if (arr.size() > 0) {
        sz = max(sz, (int)(dp[arr[0]].size()) - 1);
    }
    for (int i = 0; i <= sz; i++) {
        ll sum = 0;
        vector<int> mas;
        for (auto to : arr) {
            int need = to;
            if (to == r) {
                need = v;
            }
            if (dp[need].find(i) == dp[need].end()) {
                sum += val[need];
                mas.pb(e[need]);
                continue;
            }
            sum += dp[need][i].first;
            mas.pb({dp[need][i].second + e[need] - dp[need][i].first});
        }
        sort(mas.rbegin(), mas.rend());
        if (arr.size() < i) {
            for (auto to : mas) {
                if (to < 0) {
                    break;
                }
                sum += to;
            }
            dp[v][i].first = dp[v][i].second = sum;
        } else if (i == 0) {
            dp[v][i].first = sum;
        } else {
            ll bst = sum;
            dp[v][i].second = sum;
            for (int j = 1; j <= i; j++) {
                sum += mas[j - 1];
                if (j < i) {
                    dp[v][i].second = max(dp[v][i].second, sum);
                } else {
                    dp[v][i].first = max(dp[v][i].first, sum);
                }
            }
            dp[v][i].first = max(dp[v][i].first, dp[v][i].second);
        }
    }
}

void zhfs(int v, int p) {
    for (auto to : g[v]) {
        if (to.first != p) {
            zhfs(to.first, v);
            val[v] += to.second + val[to.first];
        }
    }
}

vector<long long> minimum_closure_costs(int N, vector<int> u, vector<int> v, vector<int> w) {
    n = N;
    ll sum = 0;
    for (int i = 0; i < n - 1; i++) {
        g[u[i]].pb({v[i], w[i]});
        g[v[i]].pb({u[i], w[i]});
        sum += w[i];
    }
    vector<ll> ans;
    zhfs(0, -1);
    dfs(0, -1);
    for (int i = 0; i < n; i++) {
        if (i < dp[0].size()) {
            ans.pb(sum - dp[0][i].first);
        } else {
            ans.pb(0);
        }
    }
    return ans;
}

#ifdef LOCAL

int main() {
  int N;
  assert(1 == scanf("%d", &N));

  std::vector<int> U(N - 1), V(N - 1), W(N - 1);
  for (int i = 0; i < N - 1; ++i) {
    assert(3 == scanf("%d %d %d", &U[i], &V[i], &W[i]));
  }

  std::vector<long long> closure_costs = minimum_closure_costs(N, U, V, W);
  for (int i = 0; i < static_cast<int>(closure_costs.size()); ++i) {
    if (i > 0) {
      printf(" ");
    }
    printf("%lld",closure_costs[i]);
  }
  printf("\n");
  return 0;
}

#endif

Compilation message (stderr)

roads.cpp: In function 'void dfs(int, int)':
roads.cpp:53:50: warning: narrowing conversion of '((dp[need].std::map<int, std::pair<long long int, long long int> >::operator[](i).std::pair<long long int, long long int>::second + e[need]) - dp[need].std::map<int, std::pair<long long int, long long int> >::operator[](i).std::pair<long long int, long long int>::first)' from 'long long int' to 'std::vector<int>::value_type' {aka 'int'} [-Wnarrowing]
   53 |             mas.pb({dp[need][i].second + e[need] - dp[need][i].first});
roads.cpp:56:24: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   56 |         if (arr.size() < i) {
      |             ~~~~~~~~~~~^~~
roads.cpp:67:16: warning: unused variable 'bst' [-Wunused-variable]
   67 |             ll bst = sum;
      |                ^~~
roads.cpp:21:8: warning: unused variable 'sum' [-Wunused-variable]
   21 |     ll sum = 0;
      |        ^~~
roads.cpp: In function 'std::vector<long long int> minimum_closure_costs(int, std::vector<int>, std::vector<int>, std::vector<int>)':
roads.cpp:103:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |         if (i < dp[0].size()) {
      |             ~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 7 / 7
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 0 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22